Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of a first image in a sequence of a displayscreen or portion thereof with transitional graphical user interface,showing our new design;

FIG. 2 is a front view of a second image thereof; and,

FIG. 3 is a front view of a third image thereof.

The appearance of the display screen or portion thereof withtransitional graphical user interface sequentially transitions betweenthe images shown in FIGS. 1-3. The process or period in which an imagetransitions to another forms no part of the claimed design.

The outermost broken lines illustrate a display screen and form no partof the claimed design. The remaining broken lines, including the brokenline showing of text, illustrate portions of a graphical user interfaceand form no part of the claimed design.

CLAIM We claim the ornamental design for a display screen or portionthereof with transitional graphical user interface, as shown anddescribed.